(1) Field of the Invention
This invention relates to shaft seals, and more particularly to turbine engine shaft seals.
(2) Description of the Related Art
In turbomachinery applications, it is often necessary to provide a seal between a rotating shaft and a housing element. At the seal, the shaft typically has symmetry around a central axis (e.g., the shaft has a cylindrical surface area). The shaft axis is normally coincident with the axis of rotation and with an axis of the housing in which the seal is mounted. However, vibration may induce small local oscillatory excursions of the axis of rotation. Brush and labyrinth seals may have sufficient compliance in their respective bristle packs and labyrinth teeth to accommodate relatively minor excursions. To accommodate greater excursions, there may be a non-rigid mounting of the seal element to the housing. This mounting permits excursions of the shaft axis to radially shift the seal relative to the housing to avoid damage to the seal.